I have a new two stage 5 ton heil installed in my

A 5 ton unit on a 2300sf house seems too big.
The only way to tell for sure is to have a professional come out and do a heat load calculation. I understand this is an old house with limited insulation, but many other factors are involved in determine the unit capacity needed including windows, overhangs, infiltration, trees/bushes, house position, etc.

An oversize A/C unit will cause the exact problem you are having. It cools so fast that it doesn't have time to remove the humidity. Please check this and if this is the problem then a band-aid solution is to add the dehumidifier. The correct solution is to install the correct A/C unit (I know, too much $$).

Also, you need to make sure the condenser unit (outdoor) and the evaporator unit (indoor) are correctly matched. Ask your A/C tech to check.

Also, check that the fan is operating at the correct airflow. Too much airflow and you'll have high humidity in the house. Again, ask your A/C tech.

Finally, check that the ductwork is properly sized. Too small or too large will cause you problems.

If nothing comes up, also check for infiltration. This is outside air getting into the house. Check all the obvious places such as around doors, windows, cracks in the wall/ceilings, etc. But also check that air is not getting sucked into the return air duct due to leaks or improper installation. This is all too common. Everything needs to be sealed and tight on the return air path. Remember, this duct is "sucking" air and any leak will **** in hot, humidity air into your A/C unit and then into your house.

I hope this leads you to the problem. Good Luck!

If this information was useful, please select YES to the first two rating questions. Good Luck and thank you!